Conjugated polyelectrolytes (CPEs) are promising hole transport materials for perovskite solar cells, whereas their severe intermolecular aggregation significantly affects the device performance. Here, long-chain alkyl imidazolium ionic liquid (IL) of 1-dodecyl-3-methylimidazolium bromide ([C₁₂mim]Br) and conjugated polyelectrolytes of potassium poly[3-(4-carboxylatebutyl)thiophene (P3CT-K) are combined with different mass ratios. The UV–vis spectra and dynamic light scattering studies indicate that the aggregation behavior of P3CT-K is suppressed by IL, thus obtaining a smoother hole transport layer for the latter device fabrication, which efficiently improves the film quality of perovskite absorber and enhances the hole transport at the interface. As a consequence, the inverted PSCs based on P3CT-K/IL film as the HTL show considerable improvement in power conversion efficiency (PCE), from 16.21% to 18.81%, compared with pristine P3CT-K based device. These findings indicate that IL can effectively inhibit the aggregation of CPEs, providing a new pathway to further improve the performance of PSCs based on CPEs interlayer.

共轭聚电解质（CPE）是钙钛矿型太阳能电池的有前景的空穴传输材料，而其严重的分子间聚集会显着影响器件的性能。在此，溴化1-十二烷基-3-甲基咪唑鎓的长链烷基咪唑鎓离子液体（IL）（[C ₁₂mim] Br）和聚[3-（4-羧甲基丁基）噻吩钾的共轭聚电解质（P3CT-K）以不同的质量比组合。紫外可见光谱和动态光散射研究表明，IL抑制了P3CT-K的聚集行为，从而为后者的器件制造获得了更光滑的空穴传输层，从而有效地改善了钙钛矿吸收剂的膜质量并增强了空穴在接口上传输。结果，与基于P3CT-K的原始器件相比，基于P3CT-K / IL膜作为HTL的倒置PSC的功率转换效率（PCE）显着提高，从16.21％提高到18.81％。这些发现表明，IL可以有效抑制CPE的聚集，提供了进一步改善基于CPE中间层的PSC性能的新途径。